Deepest Dish Broccoli Cheddar Quiche

1. Prepare the Crust

Combine flour and kosher salt in a large bowl. Add chilled butter and blend until the mixture resembles coarse cornmeal. Gradually stir in cold water until dough comes together. Shape into a disk, wrap, and chill for at least 2 hours or up to 4 days.

2. Roll Out and Fit the Dough

Roll out the dough on a floured surface to fit a 9-inch springform pan with overhang. Drape the dough into the pan, press into edges, trim excess, patch holes, and chill while preparing the filling.

3. Prepare the Filling

Trim and chop broccoli into small florets. Melt butter in a pan over medium heat. Add onions and garlic, cook until soft. Season with 1 teaspoon salt and ½ teaspoon pepper. Whisk eggs, milk, cream, remaining salt, and pepper together in a large bowl. Stir in 2 cups grated cheddar and Dijon mustard.

4. Assemble and Bake the Quiche

Scatter onion mixture and broccoli over the crust. Pour the egg mixture over. Sprinkle remaining cheese on top. Bake at 350°F (175°C) for about 1 hour or until the center is set and the top is golden brown. Let cool slightly before slicing.